Scale Characteristics of Wild and Hatchery Chinook Salmon (Oncorhynchus tshawytscha) in the Rakaia River, New Zealand, and Their Use in Stock Identification

1993 ◽  
Vol 50 (11) ◽  
pp. 2475-2484 ◽  
Author(s):  
M. J. Unwin ◽  
D. H. Lucas
Keyword(s):  
New Zealand ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Function Analysis ◽  
Adult Population ◽  
Fork Length ◽  
Genetic Traits ◽  
Linear Discriminant ◽  
Scale Characteristics ◽  
Freshwater Zone

To distinguish between fish with potentially desirable behavioural or genetic traits, we examined scales from wild and hatchery chinook salmon (Oncorhynchus tshawytscha) in the Rakaia River, New Zealand, and a tributary, Glenariffe Stream. Scales from wild chinook with a "stream-type" life history corresponded closely to those from 1+ juveniles, but the mean size of the freshwater zone for scales from "ocean-type" adults was significantly larger than for age 0+ juveniles. Scales from fish of hatchery origin lacked a distinct freshwater zone but were distinguishable from scales from wild fish by the location of the first annulus. Linear discriminant function analysis (DFA) based on the location of the first annulus correctly identified 82–90% of the fish in a mixed adult population, increasing to 88–92% when fork length and age were included. Estimates of the number of hatchery fish entering Glenariffe Stream from 1989 to 1992, based on DFA, were consistent with independent estimates derived from coded-wire tag returns.

Changes in life history parameters in a naturally spawning population of chinook salmon (Oncorhynchus tshawytscha) associated with releases of hatchery-reared fish

1997 ◽  
Vol 54 (6) ◽  
pp. 1235-1245 ◽  
Author(s):  
M J Unwin ◽  
G J Glova
Keyword(s):  
Life History ◽  
New Zealand ◽  
Chinook Salmon ◽  
Life History Traits ◽  
Oncorhynchus Tshawytscha ◽  
Fork Length ◽  
Age At Maturity ◽  
Natural Origin ◽  
Parent Stock ◽  
Stream Type

Chinook salmon (Oncorhynchus tshawytscha) spawning runs in Glenariffe Stream, New Zealand, exhibited significant changes in life history traits following supplementation releases of hatchery-reared juveniles. Total run strength did not change but the proportion of naturally produced fish declined to 34%. Attempts to separate spawners of natural and hatchery origin were unsuccessful, and 31-48% of natural spawners are now of hatchery origin. Hatchery males were smaller at age 2 and 3 than males of natural origin, and more often matured as jacks, producing an 86-mm decrease in mean fork length over 28 years. There was no change in length at age or age at maturity for female spawners. The proportion of jacks entering Glenariffe Stream each year was positively correlated with the proportion of jacks in the ensuing cohort. Most differences between fish of natural and hatchery origin were related to hatchery rearing practices, but the decline in age at maturity among naturally produced males appears to reflect traits inherited from parent stock of hatchery origin. Hatchery releases may also favour the survival of ocean-type fry over stream-type fry, possibly reversing a tendency for stream-type behaviour to evolve in response to the lack of estuaries on most New Zealand chinook salmon rivers.

An Evaluation of Rearing Densities to Improve Growth and Survival of Hatchery Spring Chinook Salmon

2013 ◽  
Vol 4 (1) ◽  
pp. 114-123 ◽  
Author(s):  
Douglas E. Olson ◽  
Michael Paiya
Keyword(s):  
Mortality Rate ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Confounding Factor ◽  
Fork Length ◽  
High Density ◽  
Growth And Survival ◽  
Migration Timing ◽  
Rearing Density ◽  
Salmon Stock

Abstract We evaluated growth and survival of spring Chinook salmon Oncorhynchus tshawytscha reared at varying densities at Warm Springs National Fish Hatchery, Oregon. For three consecutive brood years, density treatments consisted of low, medium, and high groups in 57.8-m3 raceways with approximately 16,000, 24,000, and 32,000 fish/raceway, respectively. Fish were volitionally released in both the autumn and spring to mimic the downstream migration timing of the endemic wild spring Chinook salmon stock. Just prior to the autumn release, the rearing density estimate was 4.24 kg/m3 for the low-density group, 6.27 kg/m3 for the medium-density group, and 8.42 kg/m3 for the high-density group. While weight gain did not differ among density treatments (P  =  0.72), significant differences were found in median fork length (P < 0.001) for fish reared at different densities. Fish reared at high density exhibited the highest on-hatchery mortality rate during two brood years; however, differences in mortality rate among densities were not significant (P  =  0.20). In one brood year, adult recovery rates appeared to support the hypothesis that lower initial densities improved postrelease survival (P < 0.01). All rearing densities utilized in this evaluation were relatively low and may partially explain why more differences were not readily apparent among density groups. In addition, the volitional release was a confounding factor in our study because we were unable to quantify the number of fish released in the autumn.

Using near infrared spectroscopy to assess the composition of New Zealand aquaculture species

NIR news ◽  
2018 ◽  
Vol 29 (5) ◽  
pp. 12-14
Author(s):  
Matthew R Miller ◽  
Jonathan Puddick ◽  
Jane E Symonds ◽  
Seumas P Walker ◽  
Hong (Sabrina) Tian
Keyword(s):  
Infrared Spectroscopy ◽  
New Zealand ◽  
Near Infrared Spectroscopy ◽  
Chinook Salmon ◽  
Proximate Composition ◽  
Near Infrared ◽  
Oncorhynchus Tshawytscha ◽  
Society Meeting ◽  
Perna Canaliculus

Near infrared spectroscopy has been employed to determine the proximate composition of Chinook salmon ( Oncorhynchus tshawytscha) and Greenshell Mussels™ ( Perna canaliculus). This work was presented at the Australian Near Infrared Spectroscopy Group and New Zealand Near Infrared Spectroscopy Society meeting in Rotorua, 11–12 April 2018, where it won the best overall presentation award for Near Infrared Science (Figure 1).

Fry-to-adult survival of natural and hatchery-produced chinook salmon (Oncorhynchus tshawytscha) from a common origin

1997 ◽  
Vol 54 (6) ◽  
pp. 1246-1254 ◽  
Author(s):  
M J Unwin
Keyword(s):  
New Zealand ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Survival Rates ◽  
Adult Survival ◽  
Poor Survival ◽  
Stock Size ◽  
Hatchery Fish ◽  
Stock Recruitment

Fry-to-adult survival rates for chinook salmon (Oncorhynchus tshawytscha) from Glenariffe Stream, a tributary of the Rakaia River, New Zealand, were estimated for fish of both natural and hatchery origin. Survival of naturally produced fry, most of which leave Glenariffe Stream within 24 h of emergence, averaged 0.079% (range 0.013-1.17%). For hatchery fish released at 8-12 months, standardised to a mean weight of 38 g, survival covaried with weight at release consistently across all brood years and averaged 0.34% (range 0.008-3.28%). Survival rates for hatchery fish were four times higher than for naturally produced fry, but were extremely poor relative to their size at release. Survival rates for fish of natural and hatchery origin were positively correlated, suggesting that recruitment of both stocks is primarily controlled by common influences within the marine environment, probably during the first winter at sea. Stock-recruitment analysis for the natural population showed little tendency for recruitment to increase with stock size, suggesting that marine survival rates may be density dependent. Although the reasons for the relatively poor survival of hatchery fish are unclear, the results provide a case study in which hatchery fish appear to have a poorer ``fitness to survive'' than their natural counterparts.

Tidal movements and residency of subyearling Chinook salmon (Oncorhynchus tshawytscha) in an Oregon salt marsh channel

2010 ◽  
Vol 67 (3) ◽  
pp. 524-533 ◽  
Author(s):  
David K. Hering ◽  
Daniel L. Bottom ◽  
Earl F. Prentice ◽  
Kim K. Jones ◽  
Ian A. Fleming
Keyword(s):  
Salt Marsh ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
River Estuary ◽  
Fork Length ◽  
Full Duplex ◽  
Salmon River ◽  
Salt Marsh Habitat ◽  
Tidal Cycles ◽  
Insight Into

A novel application of full-duplex passive integrated transponder (PIT) tag technology was used to investigate movements of individual subyearling Chinook salmon ( Oncorhynchus tshawytscha ; fork length ≥ 60 mm) into and out of tidally flooded salt marsh habitat in the Salmon River estuary, Oregon, USA. PIT interrogation was effective, with mean tag detection ≥ 92%. Salmon movement peaked late during both flood and ebb tide periods, indicating that salmon did not drift passively. Most movements were in the direction of tidal currents, but 20% of individuals entered the channel against the ebbing tide. Individuals occupied the intertidal channel for a median 4.9 h and as long as 8.9 h per tidal cycle, and few were detected moving when water depth was <0.4 m. Some individuals used the channel on multiple successive tidal cycles, and others entered intermittently over periods of up to 109 days. Using an individual-based approach, we characterized diversity of juvenile Chinook salmon behavior within a marsh channel, providing insight into the value of such habitats for conservation and restoration of salmon populations.

Egg size, fecundity, and development rate of two introduced New Zealand chinook salmon (Oncorhynchus tshawytscha) populations

1998 ◽  
Vol 55 (8) ◽  
pp. 1946-1953 ◽  
Author(s):  
Michael T Kinnison ◽  
Martin J Unwin ◽  
William K Hershberger ◽  
Thomas P Quinn
Keyword(s):  
New Zealand ◽  
Chinook Salmon ◽  
Egg Size ◽  
Oncorhynchus Tshawytscha ◽  
Gonadosomatic Index ◽  
Phenotypic Traits ◽  
Egg Weight ◽  
Phenotypic Differences ◽  
Development Rates ◽  
Temperature Records

Interpopulation differences in several adult phenotypic traits suggest that New Zealand (NZ) chinook salmon (Oncorhynchus tshawytscha) are evolving into distinct populations. To further investigate this hypothesis, we compared egg sizes, fecundities, and early development rates of chinook from two NZ streams. The two NZ study populations differed in size-adjusted egg weight and gonadosomatic index, but not in size-adjusted fecundity. Egg weight, fecundity, and gonadosomatic index values for both NZ populations were different than values for chinook from Battle Creek, California, the population regarded as the ancestral NZ stock. In contrast, there was little evidence of divergence in juvenile development. Time to hatching did not differ between the two NZ study populations and heritability estimates were small with large standard errors. Evidence of a small difference in alevin growth rate may have represented an effect of yolk conversion mechanics related to egg size. Despite the similarity in development rates under shared conditions, modeling based on temperature records suggests that emergence dates in the two NZ streams may differ by 4-6 weeks, yielding significant phenotypic differences.

Vertebral fusions in farmed Chinook salmon ( Oncorhynchus tshawytscha ) in New Zealand

2019 ◽  
Author(s):  
Peter S. Davie ◽  
Seamus P. Walker ◽  
Matthew R. Perrott ◽  
Jane E. Symonds ◽  
Mark Preece ◽  
...  
Keyword(s):  
New Zealand ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha
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